In preparing a color reversal reflection print, the originals can be calssified generally into transmission originals and reflection originals. The transmission originals can be so-called slide photographs and the reflection originals can be color prints, instant photographs, printed materials, etc.
Generally, in producing color reversal reflection prints, depending upon whether the original is a transmission original or a reflection original, there will be a large difference in the exposure range of the color reversal reflection print photosensitive material. That is, in the case of transmission originals, the maximum density of the originals is about 2.8 to 3.3, and to reproduce all the information of the originals, a wide exposure scale is required of the color reversal reflection print photosensitive material; while in the case of reflection originals, since the maximum density is about 1.5 to 2.5, which is lower than that of the transmission originals, a characteristic curve that can provide enough color density in a narrow exposure range is required of the color reversal reflection print photosensitive material.
That means, for example, that if a color reversal reflection print photosensitive material having a wide exposure scale for transmission originals is used for producing a reversal reflection print of a reflection original, the exposure range is too narrow to reproduce enough cntrast of the original, or on the contrary, if a color reversal reflection print photosensitive material having characteristics suitable for reflection originals is used to produce a reversal reflection print of a transmission original, since all the density range of the original is not covered, the information at the high density part or the low density part is lost.
Therefore, in the prior art, as color reversal reflection print photosensitive material use is made of one of two types of photosensitive materials properly depending on whether the original is a transmission original or a reflection original, or a photosensitive material suitable for one of a transmission original and a reflection original is also used for the other original with the insufficient reproducibility of the original being reluctantly accepted, or a halfway photosensitive material having an intermediate characteristic between the characteristics required for both is used.
On the other hand, as for the characteristics of the currently used color reversal reflection print photosensitive materials, the following disadvantages are found.
If the exposure in printing is increased to reproduce the highlight portion such as a white part, for example, a white shirt, a relatively bright portion such as the image of one's face becomes insufficient to be reproduced because the difference in the density of the original is condensed on the print resulting in an image wherein the distinction of the difference in density is hardly recognized and the tone is lost. (The image of the original would not be reproduced on the print.)
In contrast to that, if the printing is effected considering mainly the reproduction of the image of one's face, the part where the color should be white will be developed and an image will result wherein "poor clearing" has occurred. The term "poor clearing" means that the white part has been spoiled.
Conventionally, to improve this "poor clearing", effort has been made to lower Dmin (minimum developed color density), but simple lowering of the Dmin of the characteristic curve would have been apt not to result in its effect in practical printing as expected.
Hitherto, there have been many reports suggesting how to obtain preferable characteristic curves of color photosensitive materials.
For example, to obtain preferable gradation, West German Pat. No. 1,121,470, U.S. Pat. No. 2,688,538, British Pat. No. 813,687, etc., disclose the use of two or more emulsions that are included in two layers separately. British Pat. No. 732,694 describes the use of two or more emulsions in a single layer wherein the emulsions are mixed and the highest sensitive emulsion has a sensitivity at least 8 times higher than the lowest sensitive emulsion. However, although it is expected that the linearity of the characteristic curve would be improved to a certain extent, the reproduction of the tone at the highlight portion is not enough even if these techniques are employed, so that these techniques are satisfactory neither to transmission originals nor reflection originals.
Further, Japanese patent application (OPI) No. 19024/71 (corresponding to U.S. Pat. No. 3,505,068) (the term "OPI" as used herein refers to a "published unexamined Japanese patent application") describes a reversal photosensitive material wherein two emulsions different in sensitivity are used, and a lower sensitive layer is located near the support and the lower sensitive emulsion does not contain AgI in the outer shell. In this patent, since a lower sensitive side emulsion is used so as to reduce the contrast in the lower density region of the reflection image, if this is used as a color reversal reflection print photosensitive material, the reproducibility of the tone at the highlight portion would be deteriorated further. Further, U.S. Pat. No. 4,301,242 describes a method wherein as reversal reflection photosensitive material use is made of two types of emulsions having the same grain size with a narrow distribution whose desensitizing levels are different. In this case, to produce a photosensitive material having a wide exposure scale, the change in the characteristic curve resulting from the treatment using two emulsions of different size is suppressed. The goal is to obtain a reversal reflection print photosensitive material less in the change due to the treatment. Thus, it cannot be said that it has characteristics for providing a good reversible reflection print from either transmission originals or reflection originals.